1. Field of the Invention
The present invention relates to a device for cleaning contaminants on a contact portion of an electromagnetic contactor, and more particularly, a device for cleaning contaminants on a contact portion of an electromagnetic contactor in which a magnetic force the acting direction of which is changed in time is generated to the outside of the electromagnetic contactor for cleaning contaminants generated at a contact portion thereof with an arc extinguishing method, thereby effectively and broadly performing the cleaning of contaminants.
2. Description of the Related Art
In general, electromagnetic contactor is a type of electrical circuit switching device for transferring a mechanical drive and current signal using the principle of an electromagnet, and provided in various industrial facilities, machines, vehicles, and the like. FIG. 1 is a longitudinal cross-sectional view illustrating an electromagnetic contactor in the related art used in electric vehicles. The configuration of an electromagnetic contactor for electric vehicles may include a case 1, a housing 2, a stationary contact point 3 and a movable contact point 4, and typically further include electrical actuators 5, 6, 7, 8 for driving the movable contact point 4 to control the switching of contact points by an electrical signal.
Contaminants are adhered to the contact portion (a stationary contact point and a movable contact point) of the electromagnetic contactor. The contaminants may increase a contact resistance of the contact portion and thus a surface thereof can be clearly maintained through a cleaning or conditioning operation.
A conventional method used for the cleaning operation has been carried out in such a manner that an arc is artificially generated on the contact portion to burn contaminants existing on an electrode surface thereof. FIG. 2 is a view illustrating an operation diagram according to the cleaning method. FIG. 2 is a transverse cross-sectional view illustrating a contact portion of an electromagnetic contactor in the related art. A magnetic body for arc extinction 9 is provided in a direction perpendicular to the stationary contact point 3 and movable contact point 4. An arc is generated in such a form that it is started from any one (indicated by ⊙) of the stationary contact point 3 and enters into the other one (indicated by {circle around (×)}) of the stationary contact point 3 while forming an arc shape. Here, a magnetic force (B) flowing from the top to bottom on the drawing is generated, and an arc is formed with the flow of a current (I) and thus a force according to the Fleming's left hand rule (F=B×I) is generated between the stationary contact point 3 and movable contact point 4. Accordingly, the ⊙ indicated electrode receives a force (F) exerted in the “→” direction and {circle around (×)} indicated electrode receives a force (F′) in the “←” direction, thereby cleaning contaminants on a surface of the electrode.
However, according to a contaminant cleaning method in the related art, the acting direction of a magnetic force (B) is fixed in a predetermined direction so as to generate the magnetic force (B) due to the magnetic body for arc extinction 9 fixed and provided within the electromagnetic contactor and thus forces (F, F′) generated on the arc is also exerted only in a particular direction (horizontal direction (← or →) in FIG. 2), and as a result, the cleaning range of contaminants is restricted, thereby causing a problem in which there is a limit in the cleaning performance.